The Ways Food Tricks Our Brains

In 1998, researchers from the University of Pennsylvania published a study that might strike you as kind of mean.

They took two people with severe amnesia, who couldn’t remember events occurring more than a minute earlier, and fed them lunch. Then a few minutes later, they offered a second lunch. The amnesic patients eagerly ate it. Then a few minutes later, they offered a third lunch, and the patients ate that, too. Days later, they repeated the experiment, telling two people with no short-term memory that it was lunch time over and over and observing them readily eat multiple meals in a short period of time.

This might seem like a somewhat trivial discovery, but it unveils a simple truth about why we eat. Hunger doesn’t come from our stomachs alone. It comes from our heads, too. We need our active memories to know when to begin and end a meal.

While our stomachs know exactly what food we’re eating (since they’re the organ responsible for processing it) our brains are a bit more easily tricked. In this month's Journal of Consumer Research, two studies on our brains and food open a crack into a depressing world of the eating brain's awful gullibility.

How Menus Trick Us

Calorie counts can be good things. Even if they don’t dramatically change our behavior, studies have shown that they gently nudge both foodies and restaurants toward lower-calorie fare. But a new study from JCR found that there’s an easy way to eliminate the benefit of calorie counts. If you organize all the healthy dishes into a single “low-cal” category, it ironically diminishes all of the positive effects of calorie-posting. Having a separate Health Menu lets people consider the Health Menu separately. They feel good that it’s there, and then they proceed to order the same fatty stuff they wanted to eat in the first place.

How Food Tricks Us

Simply labeling a food as “healthy” makes it taste worse. But what tricky qualities make unhealthy food taste healthy?

In a series of studies written up in the latest JCR, researchers asked participants to eat bite-sized brownies while watching TV (fun!). Some of the brownies were hard and some were soft. Subjects ate more soft brownies when they weren’t prompted by any questions. But when they were told to think about calorie content, they switched and suddenly ate more rough brownies. To the eating brain, harder-to-eat equals healthier-to-eat.

The study fits neatly into a body of evidence that suggests that foods with rough textures feel heartier and healthier, even when they have the exact same nutritional qualities as softer versions. "Granola bars, trail mixes, nuts, and many cereals, in spite of being high in calories, often are perceived to be healthy probably because” their roughness feels less luxuriant and requires more work to break into swallow-able piece, the researchers conclude. The implications of this idea are sort of fascinating for fast-food companies: If you want your greasy stuff to feel healthier, make it rougher. In fact, Burger King’s new line of fries — Satisfries — were explicitly given a rougher texture.

How Ambience Tricks Us

Temperature, lighting, smells, noise: Researchers call them “atmospherics.” I prefer to call it “ambience.” Whatever you call it, these factors have a surprising ability to distract us from our food and change how much we eat. A lit review from Insead showed that:

People eat more in restaurants when the temperature is cool, possibly because we need more energy to warm up;

Soft lighting (candlelight, in particular) puts us at ease and makes us eat for longer periods of time, while bright lights make us eat faster;

Nice smells were shown to increase soda consumption in movie-watching experiments, while awful smells make us feel full faster

Social distractions — particularly watching TV or eating with friends — can lead to longer periods of eating because, like the amnesic patients at the top of the article, they make us forget what we’ve just consumed.

How Rules Trick Us

When we want to be responsible (i.e. study for a test, stay on a diet), we're most successful when confronted with really obvious forms of temptation.

If you need to study and your buddy says, “we’re going to a strip club!” your brain will be like, well I definitely can’t study at a strip club, so no. But what if that friend says, “we’re going to a coffee shop, come get a latte”? A cup of coffee is a less obvious violation of studying than a lap dance. Your brain doesn’t outright reject the idea of a coffee shop immediately. Maybe you go to the coffee shop, get into a 45-minute discussion about Captain America, wind up doing the same amount of productive studying as if you’d gone to a club, and flunk the test. The lesser temptation ironically proved even more tempting—and even more disastrous.

The curse of the lesser temptation applies to food, too. Say you’re on a diet and the waiter asks if you want the Chocolate Mount Vesuvius Cake. Your brain goes wow, that is really obviously unhealthy, no way. But if the waiter offers an array of smaller, less obviously unhealthy options (pana cotta with fresh fruit!), the force of the temptation feels less obvious, and your self-regulating mechanism doesn’t blare so loudly. Researchers have consistently found that obvious violations to our diet are easily rejected. But less obvious violations lead us consistently to temptation, because they disarm our fine-tuned self-regulating mechanisms.

How Salads Trick Us

In the mid-2000s, McDonald’s got more aggressive about promoting healthy options like salads and fruit. But its turnaround in those years was due entirely to people eating more "fast-food basics" off the Dollar Menu, like cheeseburgers and fried chicken. Promoting healthy options seemed to lure wannabe-dieters into the restaurant, only to see them order the standard greasy fare.

One theory behind this weirdness is called “vicarious goal fulfillment.” It’s the idea that the mere presence of healthy options like salad at a restaurant can ironically lead to eating less healthy food. Including a healthy option in an array of unhealthy foods can lead to more indulgence, according to a CUNY study from 2013. Researchers found that including salad on a menu of sides with french fries, chicken nuggets, and baked potato increased the odds that health-concious people would order the greasy fries rather than reject all of the options. The researchers concluded that for many of us, merely considering a healthy option satisfies our goal to be healthy, giving us license to indulge in fatty foods.

How Restaurants Trick Us

“Healthy" restaurants have unhealthy consequences. A 2007 study found that we wildly underestimate 1,000-calorie meals at “healthy” restaurants like Subway considerably more than same-calorie meals at McDonald’s. “Remarkably the biasing effect of health claims on calorie estimations are as strong for consumers highly involved in nutrition as for consumers with little interest in nutrition or healthy eating,” they wrote. Previous studies found that we order higher calorie side dishes at restaurants with healthy reputations

Although obesity is a messy dish with a million ingredients, this ironic “health” halo is considered partly responsible of the fact that, between 1991 and 2001, adult obesity rates grew from 23 to 31 percent while the share of Americans eating low-calorie food grew from 48 to 60 percent.

How Labels Trick Us

We are “a country of low-fat foods and high-fat people,” Brian Wansink and Pierre Chandon begin memorably in their paper showing that “low-fat” labels can contribute to over-eating, just as previous studies showed that labeling food samples as “small” seems to reduce our consumption guilt and encourage us to eat too much.

​Labeling snacks as "low-fat” can increase consumption by as much as 50 percent, they conclude. Across three studies, they show that low-fat labels lead all consumers—particularly those who are overweight—to overeat snack foods by as much as 50 percent above their target. In this way, healthy labels that ostensibly train us to pay attention to what we eat ironically make us more mindless when we’re snacking.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.

Derek Thompson is a staff writer at The Atlantic, where he writes about economics, labor markets, and the media. He is the author of Hit Makers.